Apparatus used in connection with laying, drying, and curing concrete



1941. F. M. TOMPKINS ET AL APPARATUS USED IN CONNECTION WITH LAYING, DRYING, AND CURING CONCRETE Filed Sept. 50, 1938 NW uih .1 1 M T0122 kins W 77 Era 25m 51 Ho; 1 WA 6.

" I Patented Nov. 11, 19 41 1 UNITED STATES 2.26am i PATENT OFFICE mm'rus USED IN commas wrrn LAYING, can-re Francis M. Tompkins and name, AND "conne -con Chesterbrook, Va; V Application September :0, 193a, serra nonsense 2 Claims. (01. 72- 1291; .7

This invention relates to apparatus used in connection with laying, drying and curing concrete and other plastic materials; and more particularly, screed supporting devices which may be quickly adjustable to difierent levels and permit the removal of the top portion of the screed supports withoutdisturbing the lower portion I floated to an equal depth thereover, will retain" the unevenness of the form slab which often sags. These wooden pegs are unsatisfactory, because they must be removed while the concrete is still wet, thus mussing up the fresh concrete, and thus making it necessary to refinish the entire area after the screeds have been removed.

Often the pegs are diflicult to remove, or are.

overlooked. If the wood is left in the concrete, whether it is on the ground or on a supported slab, it makes poor construction. .In either case, moisture will travel along the pegs, in the first case from above, and in the second,'up through the ground.

In the use of mechanical screed holders, either they must be left in the concrete with an objectionable projection which must be knocked off after the concrete sets, or removed before the concrete sets which results in the concrete being disturbed and disfigured. With the mechanical screed holder of the prior art, the screed must be lifted before the screed holder can be removed, and since the screed holder must be removed before the concrete sets, the person removing the screed holder must walk on the concrete, disturbing the surface and requiring a great deal of refinishing.

, The principal object of our invention is to provide a system in which the screed holder may be left in the concrete until it is set. which permits the screed to remain in place, thus providing a support for a tarpaulin or other covering essential in the protection or cming of concrete. The better practice is to immediately cover the concrete with a protective blanket sons to retain the moisture during the'curing, it having been strengththanj concrete permittedto cure without such covering. Such curing is expedited in cold-weather by keeping the concrete warm; and by havingjvthe screeds perforated, steam can be 5 introduced directly incontact with the concrete underneath the covering during coldw'eather, or

additionalrmoistureprovidedin warm weather by using-water in place of steam. This system permits the immediate application of protection andcuring: thereby greatly increasing the strengthofjthe concrete, and it should be further noted that on occasions where bad weather 1 sets in 'dur in 'g a pour,- protection of large areas can be' given immediately, without detriment to the concrete. a :1 These screedf supports can also be used for 'runway supports; In placing 1 concrete with wheelbarrows or concrete carts, it is necessary to have plank runways for the carts to-run on.

These should becarrie'd by supports placed above the concrete reinforcing slab. .The present type i 1 of supports for runwayshave the same disadvantage as the present type of screed support;' i. e., they have to'be withdrawn while the concrete is wet andin doingso, muss' up the con crete. A runway support constructed like these screed supportscan be withdrawn later. quite often necessary to place itsmall amount of concrete in thecenterof a'n area alreadyfinished, thus insuring ability to get the concrete to this point without mussingiup the work already Thisfwould be particularly .ad-. r ivantageous when two course monolithic finish is required.

' Another object is to provide structure that will Y permit the removal of the top. portion of the screed holder after the concrete has set and -cured, efliciently, easily; and without mussing,

leaving but a small hole that subsequently can 40 be filled. f

Other objects of our invention will become ceeds. In the drawing;

Figure 1 is a perspective showing various stages of concrete work illustrating the use of the screed holders,- screed, and curing;

. Figure 2 is an elevation of a preferredform of screed holder;

Figure 3 is a detail of screed holder, partly broken away; and

Figure 4 is a vertical section-of a modified form of screed holder.

Referring to the drawing. in, which found that such concrete has much greater parts are designated by like numerals:-

Itis

Numeral 5 designates a screed holder having a socket formed of coiled wire, the coiled wire acting as threads 1 to receive a stem I having threads 8 formed thereon.

A U-shaped saddle i0 adapted to receive screeds H is secured to the top of steml. A tripod II, in the form of legs I3. is spotwelded to the exterior of the wire socket l. The screeds ll usually take the. form oi pipes in connected circuit extending from a boiler 14, and having apertures ii in the side to permit the dispensing of steam or water. The boiler M can be mounted on wheels for easy movement, and of course, can take various forms with valve controls for dispensing the water or steam.

A modified form of screed holder is shown in Figure 4; and comprises a single leg It in place of the tripod II, with an offset foot II with a hole l8 to receive a nail or other securing means where a floor form is used, the hole ll being clear of the leg l6, and having outturned flanges I! with the socket 8 formed therein and tapped to receive the stem 0 and saddle l0.

As actually used, the screed holder 5 will be placed in position, and the saddle i0 rotated to attain the proper level. The concrete is then poured to the elevation required which will be a point above the socket 6, but below the saddle It, as shown in Figure 2. The screeds II are placed in position on the saddle l0 and a straight edge 20 placed on the screeds to level the concrete. Tarpaulin, or other covering can then be placed over the screeds H and weighted on the edges to secure it. During freezing weather steam may be introduced through the screeds; or in hot weather, additional moisture may be secured without removing the cover. When the concrete has suiliciently cured, the covering is removed, the screeds taken up, and th saddle l0 unscrewed from the sockets 8. Sincethe sockets are-just below the surface of the concrete, and the diameter of the stem 8 approximately from threeeighths to three-quarters of an inch, this can be easily accomplished by unscrewing, without disturbing the concrete, after which, if necessary,

be easily filled a finishing operascreed holders may be removed at the proper time, without disturbing the plastic material as was formerly necessary, and that the curing operation may be greatly facilitated under all weather conditions.

Numerous variations may doubtless be devised by persons skilled in the art without departing from the principles of our invention. We, therefore, desir no limitations to be imposed on our invention, except such as are indicated in the appended claims.

What we claim is: g I

1. Apparatus for laying and curing plastic material and the like, comprising screed supports,

screeds comprising tubes supported by the screed supports and having apertures therein, the tubes being connected together to comprise a continuous length of tubing, a reservoir connected to the tubing for supplying treating fluid thereto, each screed support comprising a base portion and an upper portion, the base portion adapted to be embedded in the plastic material and having its upper end terminating below but close to the contemplated level of the surface of the plastic material, the upper portion having a screed seat above the contemplated level of the plastic material, and'being removably engageable with the upper end of the said base portion, removable after the plastic material is set without disturbing the base portion solely by manipulating the screed seat.

2. In a system for building concrete slabs wherein a plurality of screed supports having base portions and vertically adjustable top portions are set in spaced relation on a sub-support adjusted to a common screed supporting level, embedded in the concrete mass to a level above the base and part way up on the adjusting portion, the base portion being left permanently in place and the adjustable portion being removed from the hardened concrete following the employment of the screed, the improvement which comprises a screed support, being one of the said plurality,

including a stable base having 'an internally threaded socket, and an adjustable upper portion including a threaded stem screwing into said socket having a screed seat rigidly secured to its upper end, affording a handle for adjustably rotating said stem.

FRANCIS M. TONIPKINS. WILLIAM T. GRAHAM. 

